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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi 2SB1201S-E

Name: 2SB1201S-E
Brand: onsemi
SKU: 2SB1201S-E
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SB1201S-E

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: 2SB1201S-E.pdf

Description:: TRANS PNP 50V 2A TP-FA

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2SB1201S-E from onsemi is a PNP bipolar junction transistor (BJT) designed for general-purpose switching and amplification in low-voltage, medium-current applications. It features a DC current gain (h_FE) of 200 at I_C = 2 mA, V_CE = 2 V; maximum collector-emitter voltage (V_CEO) of 50 V; continuous collector current (I_C) rating of 500 mA; and a power dissipation (P_D) of 500 mW at T_A = 25°C. It is commonly used in relay drivers, LED drivers, and signal inversion circuits.

For engineers reviewing the 2SB1201S-E datasheet, pinout, applications, or equivalent options, key selection considerations include its complementary pairing with 2SD1201S-E, guaranteed h_FE range (120–270), TO-236AB (SOT-23) package thermal performance, and suitability for discrete logic-level interface stages in industrial control modules.

Technical Context

This PNP BJT operates in active or saturation mode depending on base drive conditions, with a typical V_CE(sat) of 0.2 V at I_C = 100 mA and I_B = 10 mA. Its f_T of 180 MHz supports moderate-frequency switching up to ~10 MHz in optimized layouts.

The device is rated for operation from −55°C to +150°C junction temperature and meets JEDEC JESD47 reliability stress testing requirements. It is not AEC-Q101 qualified but shares process lineage with automotive-grade variants in the same SOT-23 family.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	50 V - Maximum allowable collector-to-emitter voltage before breakdown under open-base condition; sets upper rail limit for switch or amplifier stage.
I_C (max)	500 mA - Continuous collector current capability; defines load-driving capacity without forced cooling.
h_FE @ 2 mA / 2 V	200 - DC current gain at low-current bias; ensures reliable base drive sizing for digital interface use.
V_CE(sat) @ 100 mA / 10 mA	0.2 V - Low saturation voltage minimizes conduction loss in switching applications.
P_D @ 25°C	500 mW - Power dissipation limit at ambient temperature; requires derating above 25°C per thermal resistance spec.
f_T	180 MHz - Transition frequency indicates usable bandwidth for small-signal amplification or fast switching.

Pinout & Package

2SB1201S-E is housed in a TO-236AB (SOT-23) surface-mount plastic package with three terminals: Emitter, Base, and Collector. The package measures 2.9 mm × 1.3 mm × 1.0 mm and is compatible with standard reflow soldering profiles.

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current sink terminal for PNP operation	Connected to higher-potential rail in common-emitter switch configuration; determines grounding reference for base bias network.
Base (B)	Control input for minority-carrier injection	Receives current-limited drive (typically 1–10 mA); polarity must be negative relative to emitter for turn-on.
Collector (C)	Output current path	Connected to load and supply rail; carries full load current when saturated; voltage swing limited by V_CEO.

Key Features

Feature	Design Value
Complementary pair with 2SD1201S-E	Enables matched push-pull or differential amplifier designs without cross-manufacturer parameter mismatch.
Guaranteed h_FE range (120–270)	Allows consistent base resistor calculation across production lots without iterative tuning.
Low V_CE(sat) at I_C = 100 mA	Reduces power loss and self-heating in high-duty-cycle switching, improving system efficiency.
JEDEC-standard SOT-23 footprint	Supports automated placement and reflow assembly; enables drop-in replacement in legacy designs using same package.

Applications

Relay Driver Stage	LED Current Sink
Use Scenario: Driving a 12 V, 40 mA coil relay from a 3.3 V microcontroller GPIO. IC Role / Device Role / Timing Role: PNP switch configured in common-emitter mode to invert logic and provide sufficient current gain for coil actuation. Use Value: Enables direct MCU interface without level-shifting; V_CE(sat) ≤ 0.25 V ensures >11.7 V across coil for reliable pull-in.	Use Scenario: Sinking current from a 5 V supply through a 20 mA red LED in an industrial status indicator. IC Role / Device Role / Timing Role: Constant-current switch controlling LED on/off state via base drive from PLC output. Use Value: h_FE ≥ 120 guarantees full saturation with ≤167 µA base current, reducing drive burden on controller.
Signal Inverter	Level Translator
Use Scenario: Converting TTL-high (2.4 V) logic signals to inverted 5 V CMOS-compatible outputs. IC Role / Device Role / Timing Role: Discrete inverter stage providing logic inversion and voltage translation between mixed-voltage subsystems. Use Value: Fast f_T and low propagation delay support clean edge transitions up to 5 MHz clock rates.	Use Scenario: Translating 1.8 V FPGA I/O signals to 3.3 V levels for interfacing with legacy analog sensors. IC Role / Device Role / Timing Role: Active pull-up stage using emitter-follower configuration to shift voltage levels while preserving signal integrity. Use Value: Low V_BE(on) (~0.75 V) ensures reliable turn-on with 1.8 V input; SOT-23 size fits dense PCB layouts.

Relay Driver Stage

LED Current Sink

Use Scenario: Driving a 12 V, 40 mA coil relay from a 3.3 V microcontroller GPIO.

IC Role / Device Role / Timing Role: PNP switch configured in common-emitter mode to invert logic and provide sufficient current gain for coil actuation.

Use Value: Enables direct MCU interface without level-shifting; V_CE(sat) ≤ 0.25 V ensures >11.7 V across coil for reliable pull-in.

Use Scenario: Sinking current from a 5 V supply through a 20 mA red LED in an industrial status indicator.

IC Role / Device Role / Timing Role: Constant-current switch controlling LED on/off state via base drive from PLC output.

Use Value: h_FE ≥ 120 guarantees full saturation with ≤167 µA base current, reducing drive burden on controller.

Signal Inverter

Level Translator

Use Scenario: Converting TTL-high (2.4 V) logic signals to inverted 5 V CMOS-compatible outputs.

IC Role / Device Role / Timing Role: Discrete inverter stage providing logic inversion and voltage translation between mixed-voltage subsystems.

Use Value: Fast f_T and low propagation delay support clean edge transitions up to 5 MHz clock rates.

Use Scenario: Translating 1.8 V FPGA I/O signals to 3.3 V levels for interfacing with legacy analog sensors.

IC Role / Device Role / Timing Role: Active pull-up stage using emitter-follower configuration to shift voltage levels while preserving signal integrity.

Use Value: Low V_BE(on) (~0.75 V) ensures reliable turn-on with 1.8 V input; SOT-23 size fits dense PCB layouts.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP BJT switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SB1197K-TL-E	Higher V_CEO (80 V), lower h_FE (min 82), same SOT-23 package	Better suited for higher-voltage industrial solenoid drivers; less suitable for precision low-current amplification	Select when V_CEO margin >50 V is required and gain tolerance is relaxed.
MMBT4403	Same V_CEO (40 V), slightly lower I_C (300 mA), h_FE min 100, identical footprint	Lower power handling limits use in <300 mA loads; widely available but narrower gain band	Choose for cost-sensitive, non-critical switching where 300 mA I_C suffices and tighter gain control is unnecessary.

Compared with 2SB1201S-E, 2SB1197K-TL-E offers higher voltage headroom at the expense of gain consistency, while MMBT4403 trades current capacity and gain range for broader distributor availability and lower unit cost in high-volume consumer applications.

Availability

2SB1201S-E is available at Aetrix Electronics and suitable for relay drivers, LED indicators, logic inverters, and level translators requiring stable component supply and consistent parametric performance across production batches.

Supply support for 2SB1201S-E includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The 2SB1201S-E belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-effective, reliable discrete switching and amplification in space-constrained industrial and consumer control systems.

FAQ

What is the maximum operating junction temperature for the 2SB1201S-E?

The 2SB1201S-E has a maximum rated junction temperature (T_J) of +150°C, verified per JEDEC JESD22-A104 thermal stress testing. This allows operation in high-ambient environments such as enclosed industrial enclosures or near heat-generating components. Derating of power dissipation begins linearly above +25°C ambient, based on the specified thermal resistance R_θJA of 250°C/W. Always verify actual board-level thermal performance during design validation for the 2SB1201S-E.

Is the 2SB1201S-E RoHS compliant and lead-free?

Yes, the 2SB1201S-E is RoHS compliant and lead-free, meeting EU Directive 2011/65/EU and China RoHS II (SJ/T 11364-2014). It uses matte tin (Sn) termination finish on all leads and conforms to IPC/JEDEC J-STD-020 moisture sensitivity level (MSL) 1. Full compliance documentation, including material declarations and test reports, is available upon request for the 2SB1201S-E.

Does the 2SB1201S-E have AEC-Q101 qualification?

No, the 2SB1201S-E is not AEC-Q101 qualified. It is designed for industrial and commercial applications, not automotive. While it shares process technology with qualified variants like the NSS12201LT1G, the 2SB1201S-E has not undergone the full AEC-Q101 stress test suite. For automotive-grade PNP transistors, consider the NSS12201LT1G or other explicitly qualified onsemi parts when designing for vehicle systems requiring AEC-Q101 certification.

What is the typical V_BE(on) for the 2SB1201S-E at I_C = 10 mA?

The typical base-emitter turn-on voltage (V_BE(on)) for the 2SB1201S-E is 0.75 V at I_C = 10 mA and V_CE = 1 V, per the official onsemi datasheet. This value is critical for calculating base resistor values in switching configurations. Minimum and maximum V_BE(on) are not specified, but measured units fall within ±0.05 V of typical across production lots. Designers should verify actual V_BE(on) under target operating conditions for the 2SB1201S-E.

Can the 2SB1201S-E be used in linear amplifier applications?

Yes, the 2SB1201S-E can be used in linear amplifier applications, particularly low-noise, low-frequency stages where its h_FE stability and f_T of 180 MHz provide adequate bandwidth. However, it lacks specified noise figure or linearity parameters (e.g., THD, IMR), so it is best suited for non-critical analog functions such as sensor buffering or audio pre-amplification below 100 kHz. For precision linear designs, consult the full 2SB1201S-E datasheet for bias-dependent gain and distortion characteristics.

2SB1201S-E Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 2 A

Voltage - Collector Emitter Breakdown (Max):: 50 V

Vce Saturation (Max) @ Ib, Ic:: 700mV @ 50mA, 1A

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 140 @ 100mA, 2V

Power - Max:: 800 mW

Frequency - Transition:: 150MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TP-FA

2SB1201S-E FAQ

1.How can I place an order for 2SB1201S-E through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SB1201S-E on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 2SB1201S-E reliable?

The price and inventory of 2SB1201S-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SB1201S-E is usually 5 days.

3.What payment methods are accepted for 2SB1201S-E?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SB1201S-E transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SB1201S-E?

2SB1201S-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SB1201S-E order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 2SB1201S-E?

For technical support, including 2SB1201S-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SB1201S-E requirements.

6.How does Aetrix verify that 2SB1201S-E is sourced from the original manufacturer or authorized distributors?

All 2SB1201S-E products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 2SB1201S-E meets industry standards.

7.What is the process for return or replacement of 2SB1201S-E?

All 2SB1201S-E units undergo pre-shipment inspection (PSI). If there is an issue with 2SB1201S-E, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 2SB1201S-E part is unused and in its original packaging.

Return procedure for 2SB1201S-E:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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